<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping
  xmlns="urn:nhibernate-mapping-2.2"
  assembly="SchoolDomain"                    
  namespace="SchoolDomain">
  <class name="Unit">
    <id name="Id">
      <generator class="guid" />
    </id>
    <property name="UnitDate" />
    <bag name="Marks" >
      <key column="Unit" />
      <one-to-many class="SchoolDomain.Mark, SchoolDomain" />
    </bag>
  </class>
</hibernate-mapping>